Generally, IC devices include ESD protection circuits to divert and discharge high electrical currents caused by ESD events that may occur during fabrication, handling, or normal use of the devices. Without ESD protection circuits, the high electrical currents may damage the circuits in an IC device. Advanced IC devices may utilize FinFET technology for increased component density where elements (e.g. silicon fins) of the components may be smaller and more sensitive to variations in operating conditions such as an operating voltage, input current, ESD stress, fabrication processes, etc. Without an effective ESD protection circuit, a FinFET device may be easily damaged and unable to meet required ESD specifications. Traditional ESD circuits may be inefficient (e.g. require larger silicon area), limited to a fixed operating voltage, or may be ineffective in providing sufficient protection (e.g. failing 2 kV human-body-model ESD specification test).
A diode triggered silicon controlled rectifier (SCR) is a good candidate for FinFET ESD protection, since it turns on as the applied voltage is greater than n×0.7V, where n is a coefficient for a multiple of 0.7V (e.g. 3×0.7V), and can clamp the voltage as the applied voltage is greater than a trigger-voltage (Vt1). However, different applications often need different Vt1's, and changing the device Vt1 sacrifices the device area.
Therefore, a need exists for methodology enabling formation of an efficient and effective ESD protection circuit for FinFET devices and the resulting devices.